1. Field of the Invention
This invention relates generally to a passenger seat for a motor vehicle. More specifically, the present invention relates to an adjustable lumbar support for use therein.
2. Disclosure Information
Passenger seat designers often incorporate adjustable lumbar support mechanisms in their designs to help reduce passenger fatigue experienced during extended rides. One such example is disclosed in U.S. Pat. No. 4,469,374. These systems typically provide a mechanism or inflatable device located in the seat back adjacent to the lumbar region of the passenger's back. This allows the passenger to adjust the extent to which a lumbar support member protrudes from within the seat back. As a passenger begins to experience fatigue, adjusting the position of the lumbar support member can reduce fatigue and increase customer satisfaction.
The comfort of a seat back is related to the manner the seat back distributes the passenger's weight. It has been observed by some customers that adjusting the lumbar support member outward from the retracted position can drastically alter this pressure distribution and lead to discomfort. This is especially exacerbated by adjustable lumbar mechanisms that only move the lumbar portion of the seat back forward into the passenger's back. In doing so, load is transferred from the pelvis and thorax of the passenger's back and directed to lumbar area of the passenger's back. This pressure concentration significantly detracts from the passenger's comfort.
It would be desirable to provide a passenger seat that would allow the passenger to adjust the lumbar support member through a range of positions while still providing support for the pelvic and thorax of the passenger's back.